Week 5 homework

 For the element sulfur, which pair of ionisation energies has the largest difference between them?

•  third and fourth ionisation energies

• fourth and fifth ionisation energies

• fifth and sixth ionisation energies

• sixth and seventh ionisation energies

Elements X and Y are in the same group of the Periodic Table. The table shows the first six ionisation energies of X and Y in kJ mol^–1.

What could be the identities of X and Y?

• X: Sb

  Y: As

• X: As

  Y: Sb

• X: Se

  Y: Te

• X: Te

  Y: Se

Which property of an atom does not affect its first ionisation energy?

• the atomic radius

• the number of electron shells

• the number of neutrons

• the number of protons

The first six ionisation energies of four elements are given.

 

Which element is most likely to be in Group IV of the Periodic Table?

• A

• B

• C

• D

The elements radon (Rn), francium (Fr) and radium (Ra) have proton numbers 86, 87 and 88, respectively.

 

What is the order of their first ionisation energies?

• A

• B

• C

• D

The first eight successive ionisation energies for two elements of Period 3 of the Periodic Table are shown in the graphs.

•  MgCl₂

• CaBr₂

• Na₂S

• K₂Se

 The eight elements sodium to argon are in the same period of the Periodic Table.

The equation corresponding to the first ionisation energy is shown.

X(g) → X⁺ (g) + e^–

For which of these eight elements is the electron in this equation removed from a filled orbital?

•  Mg, Al, Si, P, S, Cl and Ar

• Al, Si, P, S, Cl and Ar only

• Mg, S, Cl and Ar only

• S, Cl and Ar only

Element X has a higher first ionisation energy than element Y.

Two students state what they believe is one factor that helps to explain this.

student 1 “X has a higher first ionisation energy than Y because an atom of X has more protons in its nucleus than an atom of Y.”

student 2 “X has a higher first ionisation energy than Y because X has a smaller atomic radius than Y.”

Only one of the two students is correct.

What could X and Y be?

• X: carbon

  Y: boron

• X: magnesium

  Y: aluminium

• X: oxygen

  Y: nitrogen

• X: oxygen

  Y: sulfur

Why is the second ionisation energy of sodium larger than the second ionisation energy of magnesium?

• The attraction between the nucleus and the outer electron is greater in Na⁺ than in Mg⁺ .

• The nuclear charge of Na⁺ is greater than that of Mg⁺

• The outer electron of Na⁺ is more shielded than the outer electron of Mg⁺

• The outer electron of Na⁺ is in the same orbital as the outer electron of Mg⁺

In which pair of species do both species have only one unpaired p electron?

• Ar⁺ and C^–

•  B and Ti⁺

• F and Ga

• Se^– and Si^–